CVE-2020-5666: Mitsubishielectric Melsec Iq-r00 Firmware

High severity, CVSS 7.5. EPSS: 8.8% chance of exploitation in the next 30 days.

Uncontrolled resource consumption vulnerability in MELSEC iQ-R Series CPU Modules (R00/01/02CPU Firmware versions from '05' to '19' and R04/08/16/32/120(EN)CPU Firmware versions from '35' to '51') allows a remote attacker to cause an error in a CPU unit via a specially crafted HTTP packet, which may lead to a denial-of-service (DoS) condition in execution of the program and its communication.

Affected products

• Mitsubishielectric Melsec Iq-r00 Firmware: from 05, up to and including 19
• Mitsubishielectric Melsec Iq-r01 Firmware: from 05, up to and including 19
• Mitsubishielectric Melsec Iq-r02 Firmware: from 05, up to and including 19
• Mitsubishielectric Melsec Iq-r04 Firmware: from 35, up to and including 51
• Mitsubishielectric Melsec Iq-r08 Firmware: from 35, up to and including 51
• Mitsubishielectric Melsec Iq-r120 Firmware: from 35, up to and including 51
• Mitsubishielectric Melsec Iq-r16 Firmware: from 35, up to and including 51
• Mitsubishielectric Melsec Iq-r32 Firmware: from 35, up to and including 51

Published 2020-11-16. Last modified 2026-06-17.